Memory devices for computer systems have been increasing in size and operating frequency for years, and these increases show no signs of abating.
Computers may use multiple levels of memory. For example, a central processing unit (CPU) may have a limited amount of on-chip cache memory. Additional memory may be included on a motherboard for easy access by the CPU. This additional memory may be random-access memory (RAM.) The RAM may be included on a small-outline dual inline memory module (SODIMM.) Still more memory may be made available in the form of a hard-disk drive.
It may be desirable to be able to replace this additional memory. For example, a user may want to upgrade the memory to a faster or larger memory. Also, a user may want to be able to replace a memory that has become defective. Accordingly, it has become common to use a socket or connector to form an interface between memory devices, such as an SODIMM, and a motherboard. Using a socket or connector allows a user to remove and insert memory devices in a computer system.
It is also desirable to use memory that can operate at a higher data rate. Such memories improve system performance by being more responsive, reducing wait times, providing improved graphical or audio performance, and speeding up background operations. Faster memories are consistently being developed and users want to be able to take advantage of their increased performance.
Unfortunately, the sockets or connectors that are typically used for these memories can degrade signals, create crosstalk between signals, and otherwise reduce performance. They may also generate noise that can degrade the performance of other circuits in a device, such as wireless transceivers, audio, or other types circuits.
Thus, what is needed are structures, methods, and apparatus that provide sockets or connectors that are capable of operating at high data rates with limited crosstalk and interfering emissions.